Body operated switch apparatus for timing x-ray exposures



March 28, 1939. F. M. GULLAND BODY OPERATED SWITCH APPARATUS FOR TIMING X-RAY EXPOSURES 2 SheetsSheet Filed March 28, 1958 Stan aux-d R a1 a X YO-14 ATTOR NEYS March 28, 1939. F, M, GULLAND 2,152,045

BODY OPERATED SWITCH APPARATUS FOR TIMING X-RAY EXPOSURES Filed March 28, 1938 2 Sheets-Sheet. 2

li'Ml ulland/ ATTORNEYS Patented Mar. 28, 1939 UNITED I STATES PATENT OFFICE Frank Mercer Gulland, Syracuse, N. Y.

Application March 28,

1 Claim.

This invention relates to body operated switch apparatus for synchronizing X-ray exposures and has for an object to provide a mercury switch adapted to be mechanically operated by pulse, respiratory or other movements of a body or object, in combination with adelayed action relay, for the general purpose of timing exposures of X-ray and other photographs of moving objects such as the heart, lungs,-and so forth by making successive short exposures of the object each time it reaches the same point in its motion cycle, until the total exposure time has elapsed.

With the above and other objects in view the invention consists of certain novel details of construction andcombinations of parts hereinafter fully described and claimed, it being understood that various modifications may be resorted to within the scope of the appended claim without departing from the spirit or sacrificing any of the advantages of the invention.

In the accompanying drawings forming part of this specification,

Figure 1 is a plan view of apparatus constructed in accordance with the invention.

Figure 2 is a longitudinalsectional viewof the delayed action relay with parts in elevation.

Figure 3 is .a longitudinal sectional view of the pulse operated mercury switch.

Figure 4 is a side elevation of a mercury switch showing the same operated by respiratory movement of the chest.

Figure 5 is a longitudinal sectional view of a modified form of switch adapted to be operated by movements of the body.

Figure 6 is a longitudinal sectional View of an other modified form of switch of the pressure type.

Referring now to the drawings in which like characters of reference designate similar parts in the various views, and especially referring to Figure 3, it will be seen that the pulse operated switch comprises a frame I-Ii having spaced legs I I to which a wrist strap 12 is buckled for mounting the device upon the wrist l3 of the subject, directly over any pulse. The frame is provided with a transparent tube l4 partly filled with a mercury column I5. The bottom of the tube is enlarged and is closed by a diaphragm 1B which is responsive to the pulse to raise and lower the mercury column.

An adjusting nut I1 is threadedly engaged with a nipple I8 through which the tube is slidably engaged. A helical spring I9 is sleeved on the tube between thenut and the enlarged base of the tube.

Switch contacts 20 are disposed within the tube 1938, Serial No. 198,576

above the mercury level and are mounted in a threaded tubular holder 2| which is threadedly engaged in'an adjusting nut '22 having a reduced end 23 engaged in an opening in the frame It. A leaf spring 24 secures the nut in the opening and permits'of the nut being turned to feed the holder 2| toward or away from the mercury tube in order to adjust the position of the switch contacts with respect to the top of the mercury column.

The adjusting nut H is screweddown and compresses the spring I9 which depresses the mercury tube until the mercury is seen to rise and fall steadily under impulse of the deforming of the diaphragm i6 by the pulse. The adjusting nut 22 is then turned to feed the holder 2| downward until contact is-made between the switch contacts 20 and the mercury column [5 at each rise of the mercury column.

The switch controls a primary circuit indicated by wires 25 in Figure 1 and energized by a battery 26. The circuit wires 'are connected to the input of a delayed action relay 21 shown best in Figure 2.

The delayed action relay is for the purpose of converting the individual electrical impulses in the primary circuit, which are of undetermined and perhaps irregular length, into impulses in the secondary circuit which are controllably short, absolutely uniform, timed by the beginning only of the primary impulse, and adjustable to occur automatically at any desired time after the primary impulse begins, up to nearly one whole motion cycle of the object. It comprises a frame 28 having mounted thereon a solenoid 29 which is energized by the primary circuit. A tubular iron core or plunger 30 is slidably mounted in the solenoid and is provided with a flange 3| at the top to limit its fall, as well as for a purpose later described.

A non-ferrous stem 32 is slidably mounted in the tubular plungerand is provided at its upper end with a secondary bridging circuit closer 33. The tube is provided at its lower end with a retarding piston 34 which slidably fits in the cylinder 35 having an outwardly flared open upper end 36. Retarding movement of the piston is controlled by the amount of opening of a valve 31 in an air pipe 38 which communicates at one end with the atmosphere and at the other end opens through a port 39 into the cylinder.

The bridging circuit closer 33 is insulated from the stem and is adapted to bridge secondary switch contacts 4| which are mounted upon an insulating diaphragm 42 carried by one end of a helical spring 43. The purpose of the spring is to cushion shock of impact of the bridging contact 33 and also this spring supplies the initial impetus downward to the stem 32. The opposite end of the spring is secured in a cup 44 having a tubular stem 45 which is free to slide on a fixed rod 46. This permits the spring to release bell crank levers 41, the purpose of which will presently appear.

When the plunger 30 is moved upwardly by energizing of the solenoid the flange 3| moves upwardly and comes to rest on top of leaf springs 48 which are carried by pivoted levers 49 con trolled by springs 50 to overlap and engage the bell crank levers 41 through lips 5| as shown. This upward movement of the plunger actuates a spring 5| which is sleeved upon the stem 32 and the spring raises the bridging contact 33. As the stem 32 rises it pulls upward the piston 34 which fits closely in the cylinder 35, creating a suction which will delay the speed at which the stem rises depending upon the amount of air allowed to enter the cylinder through the valve 31. The piston rises at an even, predetermined rate, until it reaches the flared portion of the cylinder, where air rushes around the edges of the piston and wholly releases the assembly of the stem 32 so that it shoots up to quickly close the secondary circuit at the contacts 33 and 4|.

There is a slight dwelling of the bridging contact 33 on the contacts 4| due to the cushioning action of the spring 43, and this will be short if the spring 43 is strong and will be longer if the spring is weak, thus timing the length of each X- ray exposure.

After the spring 43 is compressed it actuates the bell cranks 41, which move the levers 49 to withdraw the springs 48 from underneath the flange 3| and release the plunger 30 allowing it to drop to initial position for the next cycle if the primary circuit is by this time open, or allowing it to be pulled down to the electrical center ready to drop and wait for the next cycle if the primary circuit is still closed.

As the piston 34 returns to the cylinder a valve 40 carried by the piston will open under action of the accumulated air pressure and thus allows a quick drop. Meanwhile the springs 50 return the levers 49, bell cranks 41, and tubular stem 45 to initial position. Should the voltage or current to be handled by this relay be excessive for the action above described an ordinary relay indicated by broken lines at 52 in Figure 1 may be connected in the secondary circuit between it and the X-ray tube. 7

When the mercury switch is to be used in con nection with respiratory movements it may, as in Figure 4, be clamped by a clamp 53 to a supporting arm 54 of any preferred type. A lever 55 is hinged to the arm as shown at 56. The free end of the rod is disposed on top of the chest or'diaphragm. A spindle 51 is adjustably secured to the rod by a conventional swivel clamp 58 so that a head 59 on the spindle will engage underneath the enlarged bottom of the mercury tube I4. The switch is then adjusted as previously described in connection with pulse movements. The point of the reciprocatory cycle to be photographed may be selected roughly by adjustment of the mercury switch, and the delayed action relay may be used for fine adjustment.

In Figure 5 there is shown a modified form of switch which may be substituted for the mercury switch. In this form of the invention the primary circuit switch contacts 60 are carried by a threaded holder 6| engaged through a nut 62 which is carried by the top of a casing 63. A movable circuit closing contact 64 is secured to an arm 65 which projects from a stem 66 which projects through the bottom of the casing. The stem is connected to a lever 68 which is pivoted at one end as shown at 69 to the bottom of the casing and is adapted to bear against some movable part of the body as indicated at 10. The casing may be adjustably secured to a standard 1| of any desired type.

A still further modified form of the invention is shown in Figure 6. This form of the invention is a conventional pressure gauge in which a Bourdon tube 12 is provided at the free end with a bridging contact 13 adapted to engage stationary switch contacts 14 of the primary circuit, these latter contacts being mounted upon and insulated from the casing 15 of the device. This switch is an alternative for the mercury switch shown in Figure 3, and is connected to a pressure bag, which ist applied and inflated as in a sphygmomanome er.

From the above description it is thought that the construction and operation of the invention Eli/1'11 be fully understood without further explana- What is claimed is:

A delayed action relay comprising a solenoid operated hollow plunger, a stem slidably mounted in the plunger, a spring sleeved on the stem, heads on the plunger and stem engaged in opposite ends of the spring whereby the spring will be compressed by relative movement of the plunger and the stem, means for releasably engaging the head on the plunger to hold the spring in compression, a dash pot retarding device connected to the ste.. for retarding movement of the stem by said spring when the plunger is attracted by energizing of the solenoid, a pair of switch contacts, a spring disposed adjacent to said contacts and adapted to be compressed by the head of the stem to cause a dwell or the head on the contacts in circuit closing position due to the cushioning efiect of the last named spring, and means connected to the last named spring for releasing said plunger to permit return of the stem to neutral position after each actuation.

FRANK MERCER GULLAND. 

